My husband was exposed to infectious mononucleosis at his job. He takes enbrel and when he went for his refill appt he was tested for mono and the test was positive. I have been sick for 5 weeks ( sore throat with white spots, swollen glands, exhaustion, headache , body aches, occasional low grade fever , sinus congestion and chest congestion. I had a test for mono 1 week after symptoms appeared and it was negative (mono spot test) and I had one a week ago and still negative. I am not feeling better and am now nauseous a lot of the time Can there be a false negative test